Comparison Studies on Complexation of Molybdenum(VI) with Aspartic Acid And Glutamic Acid in Different Dielectric Constants1

Equilibria of the reaction of molybdenum(VI) with L-aspartic acid (Asp) and L- Glutamic acid(Glu) have been studied by spectrophotometric measurements in mixed solvent systems at an ionicstrength of 0.2 mol/dm3 sodium perchlorate, employed (15, 20, 25, 30± 0.1°C) at pH ranges of 3.2to 5.5 with a high ratio of ligand to metal. The stability constants of the complexes and theresulting free energy changes are presented. The effect of solvent systems on protonation andcomplexation are discussed. Linear relationships are observed by plotting logK versus 1/D , whereK and D show stability and dielectric constants, respectively.